A collaboration between Prof. Houk (UCLA) and Prof. Aviyente (Bogazi, University, Istanbul, Turkey) on modeling the asymmetric Claisen rearrangement is proposed to the Fogarty International Research Collaboration Award. The goal of the parent project entitled "Steroselectivities of Synthetic Organic Reactions" is to develop computational methods to explore and predict stereoselective organic reactions. New quantitative computational models will be devised to aid in the understanding and design of stereoselective reactions. The results will be of considerable importance for the development of new methods for synthesis of enantiomerically pure pharmaceuticals. The specific aim of the FIRCA proposal entitled "Steroselectivities of the Ireland-Claisen Rearrangement" is to analyze the steroselectivity of the Ireland-Claisen rearrangement by modeling the chair versus boat transition state for this reaction. The ultimate goal is to develop a theoretical understanding of the factors that control which stereoisomer will be formed in a reaction that creates or modifies stereocenters.